I recently brozed through my younger brother's card set and saw his Japanese cards. Among them, he had threeof the cards you mentioned: Dark Muk, Dark Grimer (Or Evil Grimer) and Misty's Tears. I just thought I could share my opinion with you.
I don't think there is anything wrong with Misty's Tears. Sure, it's quite clear that the artist drew her naked, but seriously, there is nothing really offensive about it. Her arm is in the way, and you cannot see 'anything'. It's amazing that Japan, a nation known for it's conservitive nature, claims there is nothing wrong about this card, but America, known for it's rauch like Jerry Springer and Spice Channels, claim this is offensive.
In another case, about the Dark Grimer card, I can see why people are saying that it needs to be changed. It is clear that Grimer sneaking a glance, but if your article about Slutty Schoolgirls is true, then it's clear that it was meant for humor. On top of which, most of the card players are young children that really don't get it. And when adults step into the picture, they criticize everything that children play with. It's not a big deal; it is just meant for humor.
Now, for the Dark Muk (Evil Muk), this is clearly a case of humor, just like the Dark Grimer (Evil Grimer) card. In the TV show, he only has three fingers, so how can he help it? I don't think the artis really meant for Muk to flip the bird because of this reason.
Now, if I may be so bold, the US has clearly looked over the wrong Pokemon cards. Take Brock's Sandshrew, whose attack is Sand Hell. Now, if America really wanted to say something, they should ridicule that and make a fuss over it.
Thank you for letting me vent my frustrations.
 From
St. Nina